In a business wireless communication system, when replacing the existing system with a new system, it is often difficult to replacing everything including wireless terminals and a wireless relay system, from a viewpoint of cost or a viewpoint of keeping the stability of the system. Therefore, a method is adopted in which a lot of time is spent for transition to the new system. During the transition period, however, wireless terminals operating on the two different systems are required to alternatively receive signals of both of the systems to wait for a call thereto. In this case, there is a problem that, if there is any system that has to always wait for a signal from a relay station, and there is a call from the system while a wireless terminal is waiting for a signal from the other system, the wireless terminal cannot receive the call. As a method for extending a function by utilizing a control channel signal, a method for changing a control channel to a voice channel, for example, is proposed in Japanese Patent No. 2724917.
The present invention has been made to effectively solve the above problem in the conventional technique, and its object is to provide a wireless communication method for waiting for call signals of two different wireless communication systems with a single reception frequency, a wireless communication system using the same and a wireless terminal thereof.